Which of the diagrams shown in the figure represents the variation of the total mechanical energy of a pendulum oscillating in water as a function of time?

$A$ simple pendulum oscillates in air with time period $T$ and amplitude $A$. As the time passes,

In damped oscillation,the graph between velocity $(V)$ and position $(x)$ will be:

When an oscillator completes $100$ oscillations,its amplitude is reduced to $\frac{1}{3}$ of its initial value. What will be its amplitude after it completes $200$ oscillations?

What is the amplitude of a damped oscillator if time becomes $t = 2m$?

For a damped harmonic oscillator governed by the equation $m \frac{d^2x}{dt^2} + b \frac{dx}{dt} + kx = 0$, find the time $t$ after which the mechanical energy becomes half of its initial maximum value.